http://hdl.handle.net/123456789/119 Sun, 19 Apr 2026 13:58:59 GMT 2026-04-19T13:58:59Z http://hdl.handle.net/123456789/2185 EFFICACY OF EXTRACTS OF Datura metel L. AND Euphorbia hirta L. AS PRESERVATIVES FOR BAMBOO (Bambusa vulgaris) AGAINST INSECT AND FUNGI ATTACKS AREGHAN, Sylvester Ehiagwinah Lignocellulosic materials are susceptible to bio-degradation. Therefore, preservatives are used to enhance their durability for various applications. The toxic nature of synthetic preservatives is encouraging the use of bio-preservative. Bio-preservatives from lignocellulosic extracts though a viable alternative are neither readily available nor their efficacy fully known. This study was therefore designed to evaluate the efficacy of extracts of Datura metel (Dm) and Euphorbia hirta (Eh) as bio-preservatives for Bambusa vulgaris (Bv) against termite and fungi attacks as well as its effect on the laminated board strength. The Dm, Eh and Bv samples were sourced in Ejiooku, Akinyele Local Government, Ibadan, Nigeria, and authenticated in Herbarium of the Forestry Research Institute of Nigeria. Phytochemical screening and characterisation of the extracts were determined by gas chromatography and mass spectrometry. Chemical constituents of the extracts were determined using AOAC procedures. Bio-preservatives were formulated from extracts at 0, 25, 50, 75 and 100% concentrations using ASTM procedures. The Bv culms were sampled from top, middle 1, middle 2 and base, cut into strips (60×20×4 mm) and soaked in the preservatives for 72 hours. Treated samples and control were sub-divided into A, B and C groups. Group A was subjected to termite (Macrotermis bellicosus) attacks for 12 months, while groups B and C were subjected to brown (Sclerotium rolfsii) and white rot (Pleurotus florida) fungi for 6 months in accordance with ASTM procedures. Weight Loss (WL) analyses were done to evaluate the potency of the formulated bio-preservatives, while its effect on gluability of Bamboo Laminated Block (BLB) were also investigated using ASTM procedures. Data were analysed using descriptive statistics and ANOVA at α0.05. Flavonoids (0.11 and 0.12 mg/g), saponins (0.31 and 0.28 mg/g) and tannins (0.04 and 0.03 mg/g) were obtained from Dm and Eh, respectively. Bicyclo [3.1.1] heptanes, 2, 6, 6-trimethyl (1α, 2β, 5α) were major chemical constituents in the two extracts. The presence of these metabolites and chemical constituents formed the basis for their utilisation as preservatives. The WL in group A ranged from 0.62±0.29 to 0.83±0.50 and 0.77±0.40 to 0.96±0.61 for Dm- and Eh-treated samples, respectively, indicating that treated samples resisted termite attack better than control (1.75±0.57). The group B WL ranged from 1.22±0.42 to 1.89±0.33 and 0.76±0.58 to 1.86±0.69 for Dm and Ehtreated samples, respectively. Those of group C ranged from 0.16±0.08 to 0.81±0.51 and 0.28±0.24 to 0.71±0.33 for Dm and Eh-treated samples, respectively. This implied that treated samples were adequately protected against brown and white rot fungi attack compared to control. There were significant variations in WL from top (1.89±0.33) to base (1.25±0.40), showing that fungi attacks were least at the base and highest at the top. Shear strength for BLB ranged from 6.06 to 3.85 N/mm and 5.13 to 4.44 N/mm for control and treated samples, respectively, indicating the suitability of the preservatives as there were no significant differences. The bio-preservatives formulated from Datura metel and Euphorbia hirta extracts offered adequate protection to bamboo against termite and fungi attacks. They are suitable preservatives for lignocellulosic materials. Sat, 01 Apr 2023 00:00:00 GMT http://hdl.handle.net/123456789/2185 2023-04-01T00:00:00Z http://hdl.handle.net/123456789/1647 THE EFFECTS OF INCLUSION OF BAMBOO (Bambusa vulgaris SCHRAD) AND ACRYLIC POLYMER ON THE PERFORMANCE OF SELECTED CONCRETE BUILDING COMPONENTS AKINYEMI, BanjoAyobami Concrete is used extensively in building construction. However, it is susceptible to corrosion, moisture migration, cracking, delamination and spalling is on the increase. These may be mitigated by components reconstitution with the inclusion of non-corrosive reinforcement and water repellent additive. Literature is sparse on the combined use of bamboo (Bambusa vulgaris) and Acrylic Polymer (AP) as means of arresting these deficiencies. This study was therefore, designed to investigate the effects of the inclusion of bamboo and AP on cement blocks, roof tiles and columns. Portland Limestone Cement (PLC), sand, AP andbamboo culms were obtained locally. The culms were sun-dried to 8% moisture content, processed into 6×10×900mm strips and 2.0mm fibres. The strips and fibres were treated with bitumen (12.0% w/w) and NaOH (10.0% conc.), respectively. Blocks(150×150×150mm) at four bamboo fibre levels(0,0.5,1.0,1.5%)and AP(0,5.0,10.0,15.0%) by mass of cement, roofing tiles (810×910×1520mm)and columns(150×150×900mm)reinforced with bamboo strips and ferrocement mesh were produced in three replicates. Binder:sand ratio of 1:3 was used for blocks and roofing tiles, while binder:fine sand:coarse aggregate ratio of 1:3:3 was used for columns at a constant water/cement ratio of 0.58. A 813×914×1524mmvibration table was developed and used to agitate the roof tiles at a frequency of 1200 rev/mins. All composite samples were cured for 28 days except the blocks which were cured for 28, 45 and 60 days. Block density, water absorption, compressive, flexural, split tensile strength and microstructure arrangement were determined using standard methods. Accelerated ageing using Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) and effects of edge cracks on natural weathering of the roofing tiles were evaluated, while axial deflection tests were performed on the columns. All tests were performed according to ASTM, ACI and BS standards. Data were analysed using descriptive statistics and ANOVA at α0.05. Block density and water absorption were 1410-1880 kg/m3 and 1.0-2.9%, respectively, while compressive, flexural and split strength were 22.9-29.6 N/mm2; 4.0-9.9 N/mm2 and 3.0-4.9 N/mm2, respectively at 28 days; 26.2-39.2 N/mm2; 6.4-10.9 N/mm2 and 3.5-6.9 N/mm2 at 45 days; 31.9- 44.9 N/mm2; 8.3-11.7 N/mm2 and 4.1-7.7 N/mm2, respectively at 60 days. The best block property was attained at 1.5 % fibre contents and 10.0% AP with density, water absorption, compressive, flexural and split strength of 1410±57 kg/m3, 2.8±0.1%, 44.9±2.6 N/mm2, 12.1±0.9 N/mm2 and 7.7±0.6 N/mm2, respectively. The fibres and polymers created anchorage between the reinforcement and matrix. There was no significant difference in MOR (2.1–2.4 N/mm2) and MOE (457.9–877.6 N/mm2) after accelerated ageing tests. At 1.5% bamboo and 10.0% AP with ferrocement, there was no noticeable edge crack in the roof tiles after 24 months-weather exposure. Column axial deflections reduced from 3.6 to 0.3mm on inclusion of bamboo reinforcement and AP additive. Reinforcement with bamboo and addition of acrylic polymer enhanced the dimensional stability, strength and durability of concrete blocks, roofing tiles and columns. Thu, 01 Jul 2021 00:00:00 GMT http://hdl.handle.net/123456789/1647 2021-07-01T00:00:00Z http://hdl.handle.net/123456789/1645 PERFORMANCE CHARACTERISTICS OF COCONUT (Cocos nucifera L) HUSK FIBRE-REINFORCED COMPOSITE ROOFING TILES BONDED WITH SELECTED CEMENT ADMIXTURES AND CURED IN CARBON(IV)OXIDE ADENIJI, ANTHONY OLUKAYODE The ban on asbestos-cement roofing sheets in many countries due to the associated health hazards of asbestos fibre resulted in the search for alternative fibres. Environmental concerns about CO2 emissions in cement manufacturing have also necessitated research on cement admixtures and CO2 utilisation. However, limited information exists on the properties and curing of natural fibre-reinforced cement composite tiles cured in CO2 in Nigeria. This study was conducted to investigate the behaviour of coconut husk fibre-reinforced composite tiles produced with selected cement admixtures cured in two CO2 media. Coconut husk was shredded,chopped and screened into random fibre lengths of 0.5–1.9mm. Chicken Egg Shell Ash (CESA) and Rice Husk Ash (RHA), produced by incineration in accordance with standardprocedures, and Calcium Carbide Waste (CCW) were used as partial replacements for cement. Thermal-Degradation-Temperatures (TDT) of coconut husk fibre, CESA, RHA and CCW were determined using standard procedure. For flat (30x20x0.6cm3) and corrugated (40x30x0.6cm3) tile production, cement was partially replaced with 10%RHA, 10%CESA, 5%CCW, 15%RHA+15%CESA, 15%CCW+15%CESA and7.5%RHA+7.5%CCW+15%CESA,respectively based on preliminary tests. Coconut fibre content (4% w/w), water/cement ratio (0.4) and cement/sand ratio (1:2) were constant.Five replicate samples were used. Curing was done inwet and dry CO2 chambers. Density, Moisture Content (MC), Water Absorption (WA), Moduli of Elasticity and Rupture (MOE, MOR) and Thermal Conductivity (TC) of the samples were determined using standard methods. Composite microstructure was examined under Scanning Election Microscope (SEM). Flat and corrugated tiles installed on roof frames for natural weathering test in Ibadan were continuously monitored for 720 days spanning dry and wet seasons. Post-installation densities were determined. Data were analysed using descriptive and inferential statistics, and ANOVA at α0.05. The TDTs of coconut husk fibre, CESA and CCW were150, 400 and 450oC, respectively, while RHA exhibited no thermal degradation. Tile density ranged between 1.8g/cm3 (10% RHA) and 2.0g/cm3(15%RHA+15%CESA). Moisture content (6.8–11.0%) correlated positively with the density (R2=0.95-0.99).The WA values (7.5-8.8%) were relatively low. The MOE (1.5-2.8 GPa) and MOR (1.42-5.01MPa) of samples cured in wet CO2 were significantly lower compared to samples cured in dry CO2 (MOE: 12.9-29.5 GPa; MOR: 7.6-12.9 MPa). The 15%CCW+15%CESA composites cured in dry CO2 had the highest MOE and MOR. Density correlated positively with MOE (R2=0.85-0.98). Cement admixture and curing methods had significant effects on WA, MOE and MOR. Thermal conductivity ranged from 1.1 to 1.5 W/mK. The images revealed denser pores in fibre-matrix composites cured in wet CO2 than those cured in dry CO2, an indication of a stronger fibre-matrix interaction largely responsible for the superior performance of the 15%CCW+15%CESA cured in dry CO2. Weathering resulted in reduction in density largely attributable to leaching which was more pronounced in corrugatedthan flattiles. A mixture of cement, egg shell ash and calcium carbide waste reinforced with coconut husk-fibre, cured in dry CO2exhibited a strong fibre-matrix interaction and performed best as a roofing tile. Flat tiles exhibited better weathering resistance than corrugated tiles. Tue, 01 Jun 2021 00:00:00 GMT http://hdl.handle.net/123456789/1645 2021-06-01T00:00:00Z